1. Field of the Invention
The present invention relates to a noise controlled handset using active noise control in a noisy environment.
2. Related Art of the Invention
Recently, an active noise control device for silencing the environmental noise at the ear by control sound from a speaker is proposed.
This type of noise silencing device was generally structured as shown in FIG. 14. The constitution is described below by referring to FIG. 14. In FIG. 14, an output signal of an error detector 8 of a handset 13 is processed in a gain phase regulator 18, and a control sound is delivered from a control speaker 6, and is negatively fed back to the error detector 8.
On the other hand, a signal from a receiving signal input terminal 11 is combined with an output of the gain phase regulator 18, and is delivered from the speaker 6. A detection signal of a talking microphone 10 is sent to a talking signal output terminal 12.
In such conventional noise controlled handset, however, when talking in a noise environment, since the noise and the talker's voice are controlled alike, the talker is hard to hear his or her own voice, and further noise mixes into the talking microphone, and the partner of communication is also hard to hear, and natural talk was difficult in two-way communication.